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The microwave-assisted rock fragmentation has been proven to be a promising approach in reducing cutting tools wear and improving efficiency in rock crushing and excavation. Thus, understanding the influence of damage induced by microwave irradiation on rock fragmentation is necessary. In this context, cylindrical Fangshan granite (FG) specimens were exposed to microwave irradiation at a power of 6 kW for different durations up to 4.5 min. The damages of the specimens induced by irradiation were quantified by using both X-ray micro-CT scanning and ultrasonic wave measurement. The CT value and P-wave velocity decreased with increase of irradiation duration. The irradiated specimens were then tested using a split Hopkinson pressure bar (SHPB) system to simulate rock fragmentation. A momentum-trap technique was utilized to ensure single-pulse loading on the specimen in SHPB tests, enabling valid fragment size distribution (FSD) analysis. The dependence of dynamic uniaxial compressive strength (UCS) on the irradiation duration and loading rate was revealed. The dynamic UCS increased with increase of loading rate while decreased with increase of irradiation duration. Using the sieve analysis, three fragmentation types were proposed based on FSD, which were dictated by both loading rate and irradiation duration. In addition, an average fragment size was proposed to quantify FSD. The results showed that the average fragment size decreased with increase of loading rate. A loading rate range was identified, where a dramatic reduction of the average fragment size occurred. The dependence of fragmentation on the irradiation duration and loading rate was also discussed.

This research study aimed to assess the cause(s) of accelerated rate of raveling observed in the in-service asphalt pavements and its impact on the performance of these pavements under arid climatic conditions. This study is a step forward towards the overall effort to determine the best practice to deal with the premature raveling problem in the arid climatic conditions of Kuwait. Five raveled pavement sections were identified for this study. Pavement distress surveys were conducted to estimate the pavement condition indices of the selected pavement sections. Additionally, several cores were extracted from the pavement sections for postmortem investigation. The laboratory evaluation included resistance to moisture damage and rutting, extracted aggregate sieve analysis, and recovered asphalt binder penetration and performance grading (PG). The pavement distress survey results showed that all pavement sections were significantly deteriorated due to raveling, indicating significantly poor performances. Laboratory test results showed, that almost all sections exhibited significantly low resistance to moisture damage and permanent deformation, indicating a high susceptibility to raveling. Furthermore, the PG and penetration test results of the extracted asphalt binders showed that all sections exhibited significantly high levels of oxidative aging and deterioration rates for their respective in-service ages. By combining all test results, it can be concluded that the arid weather and heavy traffic conditions associated with the asphalt binder poor performance have significantly weakened the adhesion bond between the aggregate particles and the asphalt binder resulting in a major stripping and raveling problem in Kuwait.

Moringa oliefera (Moringapterygosperma Gaertner) leaves popularly known as ‘ewe igiiyanu’ in Nigeria. The current study is to develop a moringa oleifera leaves pulverizer from locally sourced materials. The proposed machine works with the shearing mechanism. The main features of the machine are coverer, auger, shaft, hopper, sprout, frame, belt, pulley, bearings and electric motor. The machine was designed, fabricated and tested fulfilling the all scientific standards During study, a solar dryer was used for drying moringa oleifera leaves at average temperature of 40–50 °C for 3 days, the solar dryer had five sets of trays arranged above each other in layers. After 3 days, the moisture contents for tray 1, tray 2, tray 3, tray 4, and tray 5 were estimated as 7.2%, 24.9%, 39.4%, 39.3%, and 45.9%. Two speeds 1000 rpm, 467 rpm of the motor was used for the evaluation of the performance of the machine, and the efficiency of the machine at these speeds was 91% and 96% respectively. Sieve analysis was used to get the fineness modulus and uniformity index of the pulverized leaves using the high and low moisture content of 45.96% and 7.17%. For 12.6 g (1000 rpm) of moisture content of 7.17% [FM:UI 3:: 6:2:2] and for 10.2 g (1000 rpm) of moisture content of 45.96% [FM::UI 4.9:: 6:4:0] for 9.6 g (467 rpm) of moisture content of 7.17% [FM::UI 3.8:: 5:4:1] for 10.9 g (467 rpm) of moisture content of 45.96% [FM::UI 3.13:: 4:4:2]. These results showed that 467 rpm machine speed and moisture content of 7.17% gives the best ratio of coarse to medium and fine of pulverized leaves, the machine can be used to produce moringa tea and moringa powder safely not using the local burr mill. Sieves of different grain sizes can be included in the machine and instrumented. The findings of this study regarding pulverizing mechanisms can also be applied to other herbs and leaves.

The data in this article are related to “Assessment of Sandcrete Blocks Manufacturers ‘Compliance to Minimum Standard Requirements by Standard Organisation of Nigeria in Southwest, Nigeria” (Ajao et al., 2018). The data shows the compliance level of Sandcrete Block Manufacturers to Minimum Standard Requirement in Southwest, Nigeria. Experimental procedures carried out on aggregates and sandcrete blocks included sieve analysis to determine grading distribution sizes and bulk density and compressive strength to determine the strength parameters. The results of the experiment were presented in charts and graphs. Keywords: Aggregates, Experimental procedure, Sandcrete blocks, Standards, Strength parameters

Drill machines used in surface mines, particularly in coal, is characterized by a very poor utilization (around 40%) and low availability (around 60%). The main purpose of this study is to develop a drill selection methodology and simultaneously a performance evaluation technique based on drill cuttings produced and drilling rate achieved. In all 28 blast drilled through were investigated. The drilling was accomplished by 5 different drill machines of Ingersoll-Rand and Revathi working in coal mines of Sonepur Bazari (SECL) and Block-II (BCCL). The drills are Rotary and Rotary Percussive type using tri-cone rock roller bits. Drill cuttings were collected and sieve analysis was done in the laboratory. Using Rosin Ramler Diagram, coarseness index (CI), mean chip size (d), specific-surface area (SSA) and characteristic particle size distribution curves for all the holes drilled were plotted. The predictor equation for drill penetration rate established through multiple regressions was found to have a very good correlation with an index of determination of 0.85. A comparative analysis of particle size distribution curves was used to evaluate the drill efficiency. The suggested approach utilises the area under the curve, after the point of trend reversal and brittleness ratio of the respective bench to arrive at drill energy utilization index (DEUI), for mapping of drill machine to bench. The developed DEUI can aid in selecting or mapping a right machine to right bench for achieving higher penetration rate and utilizations. Keywords: Drill cutting parameter, Coarseness index, Mean chip size, Specific surface area, Particle size distribution curves, Drill energy utilization index

Space conditioning has one of the highest end-use service demands in the building sector. To avoid negative effects on the energy system and the environment, efficient energy sources and technologies must be implemented to provide future heating and cooling requirements. Geothermal heat pump systems (GHPS) are one of the technologies with highest thermodynamic and cost performance; nevertheless, its performance highly depends on local geological characteristics. In this study, a thermodynamic assessment of different types of sands, that could potentially be used as energy sources for GHPS in dry regions, has been conducted. The experiment focuses on understanding the thermal behaviour of five dry sand samples with different standard sieve sizes according to ASTM designations (Nos. 50, 45, 30, 16, and 14) and moisture content capacities. Based on the obtained data, a mathematical model to predict sand temperatures has been derived considering grain size, shape and moisture content. Compared to previous models, our results show that the developed model computed more accurate approximations compared to actual temperatures, providing a robust thermal behaviour model of dry regions’ sands that could be used in building simulation tools more effectively.

Composite propellant based on hydroxyl-terminated polybutadiene and ammonium perchlorate (AP) has become the workhorse propellant for modern-day missiles and space vehicles. AP is the main ingredient and is used as an oxidizer in composite propellant and accounts for approximately 70%–80% of the composition. AP plays a vital role in tailoring the burning rate of the propellant using multimodal particle size distributions and provides strength to the propellant as filler. AP is ground to different particle sizes for use in propellant formulations to achieve different burn rates and higher solid loading. Grinding of AP leads to generation of a large surface area with excess surface energy and there is a tendency for agglomeration, segregation, caking, bridging, and no flow in silo/bin/hopper, stockpile, feeder, chute, conveyor, etc. The propensity of the problems increases with increase in the time gap between grinding and mixing operations (with all propellant ingredients). Here, various grades (particle size fractions) of AP were used in propellant formulations and characterized with respect to physical and flow properties. Physical properties that were studied were particle size, shape, density, and moisture. Particle size distribution was determined using the sieve analysis and laser light scattering technique. Powder flowability was measured using shear strength, angle of repose, and tapped-to-bulk density measurements. The values of Hausner ratio and Carr index are highest for ultrafine AP, indicating that it is a highly compressible powder, whereas Hausner ratio and Carr index are lowest for the coarse AP, which indicates its free-flowing behavior.

This chapter discusses ways in which soils are identified through suitable quantitative means such as particle size distribution, degree of plasticity, etc. The resulting values are then used to classify the soil.

In this paper the local materials used in concrete mix are studied in a manner that they can resist the aggressive marine environment and mechanical damage, which can occur at several stages during transportation, construction and installation of the pipelines. In earlier studies we succeeded in finding the Egyptian ilmenite ore adequate for concrete weight coating and already utilized for many pipeline projects in Egypt. According to the presence of about 30% titanium oxides in ilmenite composition which may be extracted to be used in others strategically fields, the object of this paper is to study and evaluate the mechanical, chemical and physical properties of another local hematite high density iron ore to be used in subsea concrete weight coating for offshore petroleum pipelines. The results indicate that the local material of Um Bogma hematite iron ore can substitute both imported iron ore and local ilmenite from Abu Ghalaga in this field to reduce the cost effective and increased economical value of local ores. Laboratory and field tests were conducted for the hematite ore forming a concrete mix, composed of hematite ore, cement and fresh water according to international concrete coating specification requirements, the ore produces a concrete mix with 190–195 pcf minimum dry density and compressive strength, after 28 days of hydration, varying from 40 to 45 N/mm2 (400–450 kg/cm2) which comply with the international standards and specifications of submarine petroleum pipeline coating. In addition, local hematite shows superior results than local ilmenite and achieves 190 pcf instead of 180 pcf in case of using ilmenite.

Fine cohesive powders are often dry granulated to improve their flowability. Roller compaction is commonly used to produce dense ribbons which are then milled. The material properties of the powder and the conditions in the roller compactor affect the strength of the ribbons, however there is no method in the literature to predict the size distribution of the product of ribbon milling. Here we introduce a method, by using the Distinct Element Method (DEM) to determine the prevailing impact velocities and stresses in the mill, with bonded spheres representing the ribbons. The bond strength is calibrated by matching experimental results of three point bend measurements and predictions from numerical simulations. The ribbons are then exposed to the dynamic conditions predicted by the DEM, by dropping them from a controlled height to cause fragmentation, and subsequently stressing them in a shear cell under the conditions again predicted by the DEM. The fragments are sheared under these conditions to represent repeated passage of bars over the fragments at the mill base. Sieve analysis is used here to determine the particle size distribution under given mill conditions. The predicted size distribution of the mill product compares well with the plant data. It is found that the mill speed and length of ribbons fed to the mill have no significant influence on the product size distribution for the range tested.

Soil laboratory testing is an integral part of geotechnical engineering. This chapter discusses sieve analysis, hydrometer tests, water content, Atterberg limit tests (liquid limit and plastic limit), permeability test, and various other tests. In addition, it explains the sieve analysis procedure. Also Atterberg limits, liquid limit tests, plasticity limits, and their applications have been described.

Size analysis of the various products of a concentrator is of importance in determining the quality of grinding, and in establishing the degree of liberation of the values from the gangue at various particle sizes. In the separation stage, size analysis of the products is used to determine the optimum size of the feed to the process for maximum efficiency and to determine the size range at which any losses are occurring in the plant, so that they may be reduced.

Pulverized fuel combustion should be efficient in terms of power generation, resulting in less unburned carbon (UBC) in ash. In this study, three types of samples from stockyard, coalfeeders to mills, and bottom ash (BA) were taken from a local thermal power plant for 12 days. Proximate analysis of stockyard coal (sub-bituminous) resulted as 9.57% ash, 37.14% volatile matter, 52.91% fixed carbon, and a gross calorific value of 6640 kcal/kg. Petrographic analysis of coal showed that more than 80% consisted of reactive macerals. Coal from coalfeeders was also analyzed in terms of moisture content and sieve analysis. BA samples were analyzed and UBC content of BA over a 12 day period changes between 0.49 and 0.71% for Unit 1 and 0.26 to 0.69% for Unit 2. A relationship was seen between the moisture content and size distribution of coal from the mill inlet with UBC in the BA. A modified population model was used to estimate UBC as a function of size distribution, moisture content, mill environment constant, boiler environment constant, and residence time. A population model was used because the grinding and combustion operations are similar in terms of formation of new particles. It is seen that the model proposed is in agreement with the experimental results. In conclusion, in order to lower the amount of UBC in ash, the size distribution and moisture content of feed coal to mills should be stabilized. © 2015 Elsevier B.V. All rights reserved.

The use of rapid sand-filtration for tertiary treatment of wastewater in Saudi Arabia is expected to increase dramatically with the implementation of the lately approved Saudi code of reclaimed wastewater and reuse. Almost all-existing tertiary wastewater-treatment plants in the Kingdom utilize imported sand for filtration. The objectives of this research project were to search for appropriate local sand, and to assess its performance in tertiary filtration of wastewater by conducting a pilot-scale filtration study. Sand samples with a size range of 1.1–3.3 mm from Riyadh and Hail cities were tested for conformity to AWWA standards for filtering materials. Hail sand was found to meet the requirements of the standards. According to sieve analysis, the effective size and uniformity coefficient of Hail sand averaged 1.8 mm and 1.44, respectively. Results of the pilot study at three filtration rates of 4, 8, and 12 m/hr, have shown that Hail sand is suitable for filtration of settled stone-trickling-filter effluents. At the rates of 4 and 8 m/hr, effluent suspended solids (SS) concentrations and turbidities as high as 9 mg/L and 3.0 NTU were obtained, satisfying the Saudi reuse quality criteria for unrestricted irrigation and recreational purposes. Results of filtration at the rate of 12 m/h showed that the turbidity criterion was exceeded slightly but the SS criterion was met. Keywords: Tertiary filtration, wastewater, local sand, effective size, uniformity coefficient, head loss

In this investigation, the statistical optic characterization approach is covered for four industrial powders, namely; gelatin, iron, tin and sodium chloride. For all of these powders few size fractions from sieve analysis are optically analyzed and the particles shape and size distributions are obtained. A discussion of the effect of these primary properties statistical distributions on some of the physical parameters (i.e. the secondary properties) including friction, flow and density is presented. A standard sample size determination technique for proper number of experimental data (i.e. particles) to obtain reliable and accurate results is utilized. Several standard statistical probability density function are attempted in order to obtain the best fit of the experimental statistical diameter histograms of particles. The Gamma probability function is found to be a suitable statistical model to fit the experimental particle diameter histograms of the four powders. Finally, a non-linear correlation is displayed between the fitted distribution function parameters and the measured secondary powder parameters.

International audience; This chapter presents methods for particle size measurements for a better understanding of the physical properties of food powders. Standard methods of defining the size and shape of irregular particles are described together with ways of handling particle size data. Practical aspects of measuring particle size distributions are covered including how powders should be sampled for particle size analysis. The many techniques available for particle size analysis are described by grouping in three types: (1) direct methods, (2) methods based on classification, (3) methods based on secondary measurements. Finally the advantages of in-line continuous measurements for process investigation are described.

The paper presents a methodology for the systematic design of operating recipes for batch cooling crystallisation systems with the aim to produce a desired target crystal size distribution. The population balance model is solved using the method of characteristics under the assumptions of a constant supersaturation and growth dominated process, yielding a simplified analytical expression for the size distribution. A method is proposed for designing the seed distribution, which can be used in conjunction with the supersaturation set-point design to shape the product crystal size distribution (CSD). The approach designs the seed as a mixture of crystals obtained from standard sieve analysis. A second approach is also proposed which uses dynamic seed addition during the batch to control the final size distribution.

This paper investigates the influence of asphalt mixture type (aggregate gradation) and compaction energy level on the degradation of aggregate during laboratory compaction. The most severe form of laboratory compaction in terms of potential aggregate degradation, i.e. Marshall (impact) compaction has been used together with a standard UK aggregate and two asphalt mixture gradations consisting of a continuous and gap-graded mixture design. The results of aggregate degradation have been determined by comparing the aggregate gradation in terms of retained aggregate per individual sieve size before and after compaction. The aggregate gradation after compaction has been determined by recovering the aggregate from compacted asphalt mixture specimens and then re-grading using the series of sieve sizes used to batch the original material. The results show that asphalt mixture type and therefore aggregate gradation has a far greater influence on aggregate degradation under compaction than alterations to the level of compaction energy within the normal compaction levels experienced in the laboratory. The gap-graded asphalt mixture experienced a greater amount of aggregate degradation after compaction compared to the continuously graded mixture. The effect of increased compaction energy level did not alter the pattern of aggregate degradation for the continuously graded asphalt mixture and only increased the degree of degradation by a small amount.

This chapter discusses that one of the methods used for determining grain size distribution is sieve analysis. After the grain size distribution has been determined, the depositional history of the rock may be inferred from graphical analysis of the grain-size distribution. The distribution of sizes of the grains in sediments is related to the availability of different sizes of particles in the parent matter from which the grains are derived; and the processes operating where the sediments were deposited, particularly the competency of fluid flow. Measurement of the grain size distribution will yield a plot of the cumulative mass percent of ranges of grain sizes versus the PHI-scale used for particles size notation, the surface area of the rock per unit of pore volume and of bulk volume, and the surface area per unit of grain volume of the sediment.

This chapter discusses particle size analysis by sieving. Sieving is particularly useful as particles are sorted into categories solely on the basis of size, independently of other properties. Woven wire sieves are often referred to by their mesh size, which is the number of wires per linear inch. Woven wire sieves have pseudo-square apertures but punched plate and electroformed sieves are available with round and rectangular apertures. Sieving consists of placing a powder sample onto a sieve containing openings of a fixed size, and agitating the sieve in such a way that particles that can pass through the openings do so. Fractionation by sieving is a function of two particle dimensions only; maximum breadth and maximum thickness for, unless the particles are excessively elongated, the length does not affect the passage of particles through the sieve apertures. The chapter presents a variety of sieve apertures that are classified as coarse, medium, and fine Measuring particle size distributions by sieving is simple and inexpensive and can give reproducible results, even when using different sets of sieves, if proper care is taken. For accuracy, it is necessary that the sieves be calibrated. It is also necessary that the sieves be checked, on a regular basis using a calibration powder, so that worn sieves can be rejected.

Publisher Summary The geometric properties of soil elementary particles, aggregates, peds, pores, exposed soil surfaces, contours, etc., are of utmost importance for understanding and managing soils. Lengths, areas, volumes, mutual positions in space, counts per range of sizes, etc., are values to operate for anyone who studies or uses soils. Both direct and indirect measurements of geometric quantities are in use in soil studies. Indirect, or proxy, geometrical measurements are common. Non-geometrical values are converted into a geometrical value using a physical model thought to be approximately valid in soils. For example, to obtain particle size distribution, time of the transport of particles of a particular size is estimated from the Stokes model of viscous flow, and then the time is converted to diameters. To obtain pore size distribution, pore radii are computed using capillary models, and pressures are converted to radii. To estimate surface area, the model of ideal monolayer is used so that masses of adsorbed molecules are converted to area values. This list can be expanded easily. Ideal geometrical objects, such as spheres, circles, and segments, are widely used as models in indirect and direct measurements in soil science. Soil particles are assumed to be spheres when the Stokes model is applied. Pores are presumed to be cylinders to compute radii of pores from capillary pressure values. Molecules are thought to be spheres in calculations of the surface area from the monomolecular coverage. Soil aggregates are viewed as spheres when their diameters are measured by the sieve analysis. Using ideal geometrical models is an approximation that introduces uncontrollable errors in the measurements.

Publisher Summary This chapter discusses the skewness of some eolian sands from Saudi Arabia. Sieve analysis of eolian sand from areas around Jeddah revealed that although most grain-size distributions are in fact finely skewed, a few coarse skewed sands do occur. Interparametric relationships of sands from the Simpson Desert do not reveal any particular pattern, except for plots of mean size versus skewness. It appears that in barchans the mean grain size is not dependent upon the position in the dune, but perhaps upon the available material and wind velocity and it varies with locality. Crests tend to be better sorted than windward and lee and all samples have positive skewness. East Jeddah samples were collected in Jeddah from eolian sheets forming a thin veneer on top of Precambrian outcrops, east of the ring-road that connects Plakkah and Madinah roads. It is found that skewness is positive in all Nafud Rumhat samples, variable at Wadi Khuleis, where, however, leeward samples taken from the avalanche face tend to be more symmetrical than others.

Publisher Summary Gravel packing is a mechanical means of controlling sand production. If properly designed and applied, this completion technique can provide adequate sand control throughout the life of a well. To obtain an effective gravel-packed completion, it is essential that the pack be properly designed using the proper gravel, screen, carrier fluid, and placement technique. Choosing the proper gravel is of utmost importance in obtaining an effective gravel pack. Both gravel size and quality should be considered in designing a gravel pack. To determine the optimum gravel size, it is essential to conduct sand sieve analysis on representative formation samples. Sieve analysis from conventional cores is preferable; however, sidewall core samples can also be used. This chapter discusses some of the methods of gravel-packing, such as open hole gravel pucks, cased-hole gravel packing, “single stage” method, and “two -stage’’ method.

This chapter presents precision particle analysis to obtain quantitative data about the size and size distribution of particles in the material. However, the exact size of an irregular particle cannot be measured. For irregular particles, it is desirable to quote the size of a particle in terms of a single quantity, and the expression most often used is the “equivalent diameter.” This refers to the diameter of a sphere that would behave in the same manner as the particle when submitted to some specified operation. The assigned equivalent diameter usually depends on the method of measurement. Hence, the particle-sizing technique should duplicate the process one wishes to control. For example, the Stokes' diameter is measured by sedimentation and elutriation techniques, the projected area diameter is measured microscopically, and the sieve-aperture diameter is measured by means of sieving. Size analysis of the various products of a concentrator constitutes a fundamental part of laboratory testing procedure. It is of great importance in determining the quality of grinding and in establishing the degree of liberation of the values from the gangue at various particle sizes. In the separation stage, size analysis of the products is used to determine the optimum size of the feed to the process for maximum efficiency and to determine the size range at which any losses are occurring in the plant so that they may be reduced. It is essential, therefore, that methods of size analysis must be accurate and reliable, as important changes in plant operation may be made on the results of the laboratory tests.

Criteria governing the optimal sieve load and duration of sieving for size classification have not been well defined in the past; particle size was generally regarded as the most significant parameter. Using size- and shape-sorted sand fractions between 32 and 250 micrometres, it has been shown that particle size, sieve load and particle shape all have an influence on sieving rates. For powders finer than 150 micrometres, particle shape is the dominant variable controlling sieving rate and the extent of sieve blinding.

Publisher Summary The chapter focuses on the determination of the radius re (re ≦ r) of the largest constriction through which the pore segment in question is accessible. The success of determining accessibilities seems to depend, to a considerable degree, on the accuracy with pore size. The distributions can be determined micrographically using polished sections of the sample. The first step to the known methods of calculating the distributions of sphere diameters are studied. These calculations are based either on the distribution of circle diameters obtained by intersecting the spheres with random planes or on the chord length distribution obtained by intersecting the spheres with random straight lines. This work is done on a high speed digital computer. The results indicate that the sphere diameter distribution can be calculated with a very high degree of accuracy on samples that can be easily handled by present-day automatic microscopes. The second step in testing the micrographic methods, the size distributions of granular materials consisting of non-spherical particles have been determined both micrographically and by standard sieve analysis. The results indicate reasonable agreement with such materials as common salt.